The aims of the proposed research are: 1) To quantify the locomotion of polymorphonuclear leukocytes (PMNs) from individuals of various races, sexes, ages and from different tissue pools. 2) Where necessary, to separate and purify subgroups of PMNs which differ in locomotive behavior. 3) To determine the types of actin and quantify and G-actin, F-actin and total actin in groups of PMNs which differ in locomotive behavior. Locomotive behavior will be quantified by analysis of time lapse videorecordings of 400-500 individual PMNs and analyzed by computer. Subgroups of PMNs which differ in locomotive behavior will be separated and purified based upon differences in adherence, rosette formation and locomotive behavior. Isoactins will be identified by two dimensional gel electrophoresis. Total actin will be measured by SDS-PAGE and DNase I inhibition. G-actin will be measured by DNase I inhibition. Actin filaments will be measured by tritiated cytochalasin B binding. The long range objectives of this study are: 1) To correlate differences in the state of actin in PMNs with differences in their locomotive behavior. 2) To identify subpopulations of normal PMNs and characterize them according to their actin content and the behavior of actin in the cells. 3) Ultimately, to apply this knowledge to understanding disease states characterized by differences in PMN locomotion.